The Announcements
View the full set of November announcements by clicking here. As more activities open up, more volunteer opportunities are coming into the chapter calendar. Opportunities and contacts, websites, and other details are available in the announcements.
COVID-19 update: Chapter meetings are now provided in hybrid format. Masks indoors and social distancing are required at the in-person meeting at Dallas College – Brookhaven. We’re tracking with CDC guidance and continue to encourage wearing masks indoors as well as social distancing. Details here.
Highlights of the meeting
Science Fair Winner: Sreya Das kicked off our meeting with a review of her project, “Hermetia illucens – Effectiveness of Bioconversion of Dairy Products.” Her project won an NTMN award at the 2021 Dallas Regional Science and Engineering Fair. With the pandemic came record dairy surpluses and extensive milk dumping, in part a result of school cafeteria closures. The black soldier fly larva is known as an effective composter. Sreya evaluated its potential role in processing waste dairy products, finding that it was able to effectively compost a range of dairy products.
New Honorary Member Stalin SM: We’re saddened to see Stalin move back to India. A very active member since 2015, he has played a key role in documenting chapter events and leading the photography committee. Bruce Stewart walked us through a light-hearted review of Stalin’s time with NTMN. He will continue chapter photo work remotely from India. The chapter unanimously approved Stalin’s honorary membership. Congratulations, Stalin!
This month’s camera roll showcased your amazing nature photos. Please keep them coming.
The Ends of the World, Are We There Yet?
Many thanks to Dan Northcut for such a compelling presentation on the five mass extinctions and their implications for the climate change we currently experience. Dan defined mass extinction as loss of a significant portion of the Earth’s biota in a geologically insignificant time.
In contrast, he described our current situation as mass depletion, but one that could morph into a mass extinction. There have been some 1,000 documented extinctions over the last 500 years but many more species have been severely depleted, a major loss of biodiversity. This doesn’t bode well but hasn’t yet reached the level of losing a major portion of living species.
Why work to understand mass extinctions? Well beyond intellectual curiosity, Dan stressed that a grasp of mass extinction processes can help us make better decisions now. The causes may be different, but there may be parallel effects to plan for, changes we can make to reduce our impact.
The five mass extinctions are named here for the old geologic period that ended and the new period following the die-off. They are:
1. Ordovician-Silurian: 439 million years ago (mya); 85% of living organisms lost.
Causes – decreased atmospheric CO2 from collision of continental plates and increased plant life, which cooled the earth and created a large ice age.
2. Late Devonian: 364 mya; 70% of marine life lost.
Driven by increasing plant life and large release of nutrients. This caused eutrophication along continental edges and yielded another ice age.
3. Permian-Triassic “The Great Dying:” 251 mya; over 96% of all species lost. Causes – Major CO2 increase from large volcanic eruption (created the basalt Siberian Traps) plus fires burned heavy vegetation and reduced ozone layer; led to global warming with acidified, anoxic, “hot tub” oceans; coral reefs died.
Parallels to today: Rate of CO2 added to atmosphere was less than or equal to our current input since the industrial revolution. Already seeing ocean pH dropping, coral bleaching such that most reefs will be dead in 30-40 years.
4. Triassic-Jurassic: 214 mya; 76% of all species lost.
Causes – massive volcanic eruptions associated with the breakup of supercontinent Pangea, created large basalt traps, increased CO2. This raised global temperatures and acidified oceans.
5. Cretaceous-Paleogene: 66 mya; 76% of all life lost, including all dinosaurs.
Dual causes – Massive 7-mile-wide asteroid strike plus 300,000 years of volcanic eruptions that produced flood basalts (Deccan Traps in India), created immediate and long-term changes.
Key takeaways: Dan encouraged us to take into account how we are living and to share climate change information with others. As a communication tool, Dan offered this Geologic Time Scale model:
– 457 meters long for the earth’s 4.57 billion years old (picture 5 football fields)
– every meter equals 10 million years and 10 centimeters equals 1 million years
– Homo sapiens has existed some 200,000 ye2 cm
– Agricultural revolution 10,000 years or 1mm
– Industrial Revolution 200 years or 1/50 millimeter, yet has accumulated atmospheric CO2 at mass extinction levels
Dan landed on an optimistic note. With recent far-reaching commitments from major auto manufacturers to move to electric vehicles, he sees more hope for positive change than he has in a long while.
Going deeper: The Sixth Extinction book by Elizabeth Kolbert
Racing Extinction, documentary film on biodiversity loss, from the Oceanic Preservation Society
The Ends of the World book on mass extinctions by Peter Brannen
The 11th Hour film from Leonardo Dicaprio
Ekspeditionen – På sporet af Vitus Bering documentary on the Danish explorer, in Russian with subtitles
We will post a recording of the meeting here when it is available.
Thanks to our guests and members for participating in this month’s meeting. I hope all feel welcome at NTMN.
Take care,
Scott Hudson
President
North Texas Master Naturalist